Producer Jon Landau last week clarified that they would be shooting the second and third “Avatar” films back-to-back, but that they were not working on the fourth film yet. Then James Cameron revealed that, if the fourth film was indeed to be made, it would be a prequel.

Tonight, we got a chance to talk to Cameron ourselves and asked him more specifically about Avatar 2 and Avatar 3. The filmmaker made an appearance at Best Buy in New York’s Union Square on Monday to discuss the new Blu-ray release of Titanic.

We asked him, since he had touched on themes of oceanographic exploration in Titanic, The Abyss and his documentaries, what aspects of that did he have left to explore in his upcoming movies.

“We’re doing ‘Avatar’ films now, so we’re making up an ocean ecosystem for Pandora,” Cameron said, “That’s gonna have less to do with the deep exploration that I’ve done than it has to do with my concerns about conservation of Earth’s oceans. The fact that we’re basically overfishing, climate change… a few degrees of temperature rise are gonna basically take out the coral reefs. All those beautiful images of the coral environments we all grew up with won’t exist in 50 years at the rate we’re going in terms of pumping greenhouse gases into the environment. These are the things that concern me.”

He added that “there isn’t a direct map between the deep ocean exploration that I’ve done and the ocean stuff that we’re doing in the ‘Avatar’ films. However, I’m going to continue in the future making documentaries and continuing explorations stuff as well because I’m always fascinated by that. We don’t have to explore the coral reefs at this point because we understand them very well. We also understand that they’re dying and they’re ultimately doomed if we don’t change our profligate ways.

“I hope that explains it, ’cause people have connected the dots directly together. ‘Oh, going to the challenger deep has a direct connection to what we’re going to see in Avatar 2,’ and that’s not the case at all. It’s all the scuba diving I did before I even started the deep ocean stuff that has more of a direct connection to Avatar 2 & 3, which by the way won’t take place completely in or under the water. That’s just part of the environment of Pandora that we’re going to see.

Twentieth Century Fox was targeting a December 2014 release date for Avatar 2 and a December 2015 release for Avatar 3.